Convert tick-based timer events to versioned ones

Instead of storing the system ticks in the timer event message
simply store a version.

Moves the version handling code into a VersionedEvent class,
inherited by WinSalTimer and AquaSalTimer.

Change-Id: I5add85031d36b3424a26a9ef798294cbfb00b2e4
Reviewed-on: https://gerrit.libreoffice.org/42959
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

3 files changed, 49 insertions, 5 deletions

diff --git a/vcl/inc/osx/saltimer.h b/vcl/inc/osx/saltimer.h
index f70bd65491b8..65247b930cfa 100644
--- a/vcl/inc/osx/saltimer.h
+++ b/vcl/inc/osx/saltimer.h
@@ -41,10 +41,9 @@ public:
     ~ReleasePoolHolder() { [mpPool release]; }
 };
 
-class AquaSalTimer : public SalTimer
+class AquaSalTimer final : public SalTimer, protected VersionedEvent
 {
     NSTimer    *m_pRunningTimer;
-    sal_Int32   m_nTimerStartTicks;  ///< system ticks at timer start % SAL_MAX_INT32
 
     void queueDispatchTimerEvent( bool bAtStart );
     void callTimerCallback();
diff --git a/vcl/inc/saltimer.hxx b/vcl/inc/saltimer.hxx
index e0179dd5fd27..983e0771ee9b 100644
--- a/vcl/inc/saltimer.hxx
+++ b/vcl/inc/saltimer.hxx
@@ -34,6 +34,7 @@
 class VCL_PLUGIN_PUBLIC SalTimer
 {
     SALTIMERPROC        m_pProc;
+
 public:
     SalTimer() : m_pProc( nullptr ) {}
     virtual ~SalTimer() COVERITY_NOEXCEPT_FALSE;
@@ -55,6 +56,49 @@ public:
     }
 };
 
+class VersionedEvent
+{
+    /**
+     * The "additional event data" members on macOS are integers, so we can't
+     * use an unsigned integer and rely on the defined unsigned overflow in
+     * InvalidateEvent().
+     */
+    sal_Int32 m_nEventVersion;
+    bool      m_bIsValidVersion;
+
+public:
+    VersionedEvent() : m_nEventVersion( 0 ), m_bIsValidVersion( false ) {}
+
+    sal_Int32 GetNextEventVersion()
+    {
+        InvalidateEvent();
+        m_bIsValidVersion = true;
+        return m_nEventVersion;
+    }
+
+    void InvalidateEvent()
+    {
+        if ( m_bIsValidVersion )
+        {
+            if ( m_nEventVersion == SAL_MAX_INT32 )
+                m_nEventVersion = 0;
+            else
+                ++m_nEventVersion;
+            m_bIsValidVersion = false;
+        }
+    }
+
+    bool ExistsValidEvent() const
+    {
+        return m_bIsValidVersion;
+    }
+
+    bool IsValidEventVersion( const sal_Int32 nEventVersion ) const
+    {
+        return m_bIsValidVersion && nEventVersion == m_nEventVersion;
+    }
+};
+
 #endif // INCLUDED_VCL_INC_SALTIMER_HXX
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/inc/win/saltimer.h b/vcl/inc/win/saltimer.h
index f87361e55ed8..06e77b171cb3 100644
--- a/vcl/inc/win/saltimer.h
+++ b/vcl/inc/win/saltimer.h
@@ -22,13 +22,14 @@
 
 #include <saltimer.hxx>
 
-class WinSalTimer : public SalTimer
+class WinSalTimer final : public SalTimer, protected VersionedEvent
 {
     // for access to Impl* functions
     friend LRESULT CALLBACK SalComWndProc( HWND, UINT nMsg, WPARAM wParam, LPARAM lParam, int& rDef );
+    // for access to m_bPollForMessage
+    friend static void CALLBACK SalTimerProc( PVOID data, BOOLEAN );
 
     HANDLE       m_nTimerId;          ///< Windows timer id
-    sal_uInt32   m_nTimerStartTicks;  ///< system ticks at timer start % SAL_MAX_UINT32
     bool         m_bPollForMessage;   ///< Run yield until a message is caught (most likely the 0ms timer)
 
     void ImplStart( sal_uIntPtr nMS );
@@ -49,7 +50,7 @@ public:
 
 inline bool WinSalTimer::IsValidWPARAM( WPARAM aWPARAM ) const
 {
-    return aWPARAM == m_nTimerStartTicks;
+    return IsValidEventVersion( static_cast<sal_Int32>( aWPARAM ) );
 }
 
 inline bool WinSalTimer::PollForMessage() const